package course17;

public class Test {
    public static void main(String[] args) {
        String a=null;
        String b="00";
        String c="12";
        String d= "34";
        a=b+c+d;
        System.out.println(a);
        String e="hello";
        char[] ch=e.toCharArray();
        String f=String.valueOf(ch[0])+ch[1];
        String g=String.valueOf(ch[2])+ch[3];
        System.out.println(f);
        System.out.println(g);
    }
}
